Methods of this kind are used in various components composed of structural elements, in particular in the aerospace engineering sector, in which methods considerations regarding the relationship between cost and weight play the most important role. In this regard, considerations that need to be included may, in view of the (increasing) complexity of structural elements, but also the number thereof, relate to process risks that could be reduced or avoided. Considerations regarding weight savings over substantially comparable methods, the integrity of the fiber structure or matrix of the structural elements produced in two different ways, and the case in which a plurality of parts that are to be produced differently may have to be combined also play a part.
The structural elements, which are to be processed, to be joined to a component and are made of a fiber-reinforced plastics material, are generally fiber-matrix semi-finished products that have to be cured under application of pressure and temperature in order to produce the component. These semi-finished products, which are often held as track-like preforms, but are not fixed in this shape, are also referred to as “prepregs” (short for “preimpregnated fibers”) and in most cases consist of a thermosetting matrix that is filled with fibers but is not cured. In this case, the matrix in question is therefore in a partially cross-linked state and cannot be liquefied again by being heated.
The mentioned semi-finished products can therefore be joined in methods of varying complexity, some of which are associated with being considerably complex. Furthermore, the structural elements to be joined can be provided with additional holding means, such as rivets, or also with reinforcing means.